Brain scans showed the cannabis users had significantly blunted dopamine responses compared with the controls who had never taken the drug.; Research links marijuana use to mental health problems: anxiety, depression, suicidal thoughts, schizophrenia and short-term psychosis.

Teen Drug Experimentation. Half of all new drug users are under the age of 18. Experimentation plays the biggest role in teenage drug use. However, experimentation is a fact of life and just because a teen has tried drugs or alcohol doesn’t mean they will become an addict.